In MTK chips, if the DRM runtime resume has not yet completed and the system enters sleep mode at the same time, there is a possibility of a black screen after waking the machine. Reduce the disable delay resolves this issue, The "backlight_off_to_display_off_delay_ms" was added between "backlight off" and "display off" to prevent "display off" from being executed when the backlight is not fully powered off, which may cause a white screen. However, we removed this "backlight_off_to_display_off_delay_ms" and found that this situation did not occur. Therefore, in order to solve the problem mentioned above, we reduced it from 100ms to 3ms (tCMD_OFF >= 1ms). This is the timing specification for the two panels: 1. Kingdisplay panel timing spec: https://github.com/KD54183/-JD9365DA_Power-On-Off-Sequence_V0120240923 2. LMFBX101117480 timing spec: https://github.com/chiohsin-lo/TDY-JD_LIB Fixes: 2b976ad760dc ("drm/panel: jd9365da: Support for kd101ne3-40ti MIPI-DSI panel") Fixes: c4ce398cf18a ("drm/panel: jd9365da: Support for Melfas lmfbx101117480 MIPI-DSI panel") Signed-off-by: Zhaoxiong Lv <lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> --- Changes between V3 and V2: - 1. Modify the commit message v2: https://lore.kernel.org/all/20240923134227.11383-2-lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Changes between V2 and V1: - 1. Modify the commit message - 2. Modify the value of backlight_off_to_display_off_delay_ms. v1: https://lore.kernel.org/all/20240915080830.11318-2-lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ --- drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c index 44897e5218a6..486aa20e5518 100644 --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c @@ -858,7 +858,7 @@ static const struct jadard_panel_desc kingdisplay_kd101ne3_40ti_desc = { .reset_before_power_off_vcioo = true, .vcioo_to_lp11_delay_ms = 5, .lp11_to_reset_delay_ms = 10, - .backlight_off_to_display_off_delay_ms = 100, + .backlight_off_to_display_off_delay_ms = 3, .display_off_to_enter_sleep_delay_ms = 50, .enter_sleep_to_reset_down_delay_ms = 100, }; @@ -1109,7 +1109,7 @@ static const struct jadard_panel_desc melfas_lmfbx101117480_desc = { .reset_before_power_off_vcioo = true, .vcioo_to_lp11_delay_ms = 5, .lp11_to_reset_delay_ms = 10, - .backlight_off_to_display_off_delay_ms = 100, + .backlight_off_to_display_off_delay_ms = 3, .display_off_to_enter_sleep_delay_ms = 50, .enter_sleep_to_reset_down_delay_ms = 100, }; -- 2.17.1
